Improvement in the process of coating metal with metals



UNITED STATES PATENT OFFICE.-

Jos. POLEUX, on NEWYORK, N. Y.

IMPROVEMENT IN THE PROCESS OF COATING METAL WITH METALS.

Specification forming part of LettersPatent No. 15,953, dated October21, 1556.

. To all whom it may concern:

Be it knownthat I, J OSEPH POLEUX, of the city and State of New York,have discovered or invented an improvement in the process of coatingiron bolts, bars, sheets, spikes, nails, and other articles of iron withmetallic alloys; and I hereby declare the following is a full and exactdescription thereof.

The nature of my invention consists in preparingiron to be coated byother metals, using therefor concentrated mineral acid, as stated below.

I prepare the iron articles to be coated by cleansing them in acid much.in the usual way;

but I do not dilute the acid, as the ordinary practice is. On thecontrary, I use it as received from the manufacturer, because by sodoing the operation of cleansing the iron is much shortened, and becauseI have discovered a mode of arresting its action on every part of anarticle submitted to it the instant its action is no longer necessary,and I therefore consume the least possible quantity. I prefer muriaticto nitric orsulphuric acid.

As soon as the articles tobe. cleansed are immersed in the acid, Idropone, two, or more small pieces of spelter among them, or pass them intothe acid with the articles. A pound of spelter would be sufficient forhalf a ton or more of spikes or bolts. The acid acts at once and rapidlyon the spelter, holds in solution what it dissolves, and precipitates afilm of it on the minutest portions of the iron surfaces the instant theacid has cleansed them, and this film protects such portions from anyfurther action of the acid while remaining in it. Without the spelterundiluted acid could not be used without great waste and injury to smallor thin articles placed in it. Articles, when not unusually rusty orscaly, are cleansed in a minute, or even less, while a longer orshorter.

time is required, according to the condition of the surfaces and thestrength of the acid. The articles are next taken out, and, withoutbeing washed, dried, or undergoing any other treatment whatever, arepassed immediately, though slowly, into the bath of melted alloy thatforms acid into the bath than when they are dried and exposed to theaction of the air. The union, moreover, is effected, keeping the surfaceclean and free from oxidation by covering it with melted tallow, andoccasionally using powdered sal-ammoniac.

The alloys forming the coating I constitute differently, according tothe use to which the coated articles are to be put, some being coatedwith tin and very limited proportions of its ordinary alloys, in whichthere is no novelty; but there are purposes where a larger proportion oflead than has everbeen used affords a better protection than tinalone-as sheathing for ships and covering of roofsand as lead, from itscomparatively low price, materially reduces the cost of the coating ..itbecomes desirable to introduce it in as'large proportion as possible forthe protection of iron. The following is the alloy which I now ployed. Ifind the union of the tin and lead v -more complete with the antimony,and without the antimony the copper. appears to be but mechanicallymixed with the lead. This alloy leaves a coating on iron almost as whiteas tin alone, the copper and antimony neutralizing the bluecolor of thelead. Thelow temperature at whichthis alloy is used affects not themalleability or tenacity of iron coated with it.

What I claim as my improvement, and desire to secure by Letters Patent,in'the process of coating iron-ware with metallic alloys, is-

The employment of muriatic, nitric, or sul phuric acid of the ordinarydegrees of concentration in commerceviz., muriatic of 18 of Baum, nitric38 of same, and sulphuric 66 of same-,without diluting them, embracingthe solution of spelter in the cleansingacid, in the proportion andmanner and for the purposes specified, and the passing the cleansedarticles directly into the metallic bath without any intermediatetreatment whatever. V

Witnesses: JOSEPH POLEUX.

LOUIS SALIN, I E. TRUcKET.

